A cover constituting the appearance of an outboard motor is generally made from an aluminum alloy to provide required rigidity to the outboard motor to be supported on a stern of a boat.
In some outboard motors, however, a cover made from a resin material is in practical use to reduce weight and cost. For example, an engine cover forming an upper half of an engine compartment and an under cover forming a lower half of the engine compartment are made from resin.
Into the engine compartment defined by a cover body consisting of the engine cover and the under cover, cables including an engine control cable for opening and closing a throttle valve, a power train control cable for switching between forward and rearward propulsion, a power supply cable, a various electrical signal transmission cable and a fuel feeding pipe are introduced.
An introduction portion for the cables is provided in the cover body. A sealing member is provided around the introduction portion and the cables to prevent ingress of water into the engine compartment.
An outboard motor having such kind of sealing structure is disclosed, for example, in Japanese Patent Laid-Open Publication No. 2001-39390.
An under cover of the outboard motor is divided into left and right portions. A right cover of the left and right divisions is formed with a horizontally notched portion in a substantially U shape. A front cover joined to the right cover is formed with a horizontally extending protruded portion fitted into the notched portion.
When the notched portion and the protruded portion are fitted together, a circular retention opening is formed between the deepest portion of the notched portion and the distal end of the protruded portion. A cable holding member made from an elastic material such as rubber is fitted into the retention opening. That is, the cable holding member is held between the notched portion and the protruded portion in a sandwiched manner. Cables are inserted through the cable holding member and retained therein. A watertight groove is formed around the periphery of the cable holding member. A flange formed around the inner periphery of the retention opening is fitted into the watertight groove, thereby forming a sealing structure.
To improve sealing performance, it is required to form the notched portion and the protruded portion with high precision.
It is also required to fit the notched portion and the protruded portion together, restraining the expansion of the cable holding member having elasticity. In either case, care should be taken in production.
It is thus desired to improve sealing and retention of cables with a sealing member (grommet), and to facilitate mounting of a cable retention cover to a cover body with high precision.